Cloaking on Google is a practice of presenting different content to your users and search engines with an intent of manipulating search rankings and also misleading users.
Cloaking in Google and SEO is a search engine optimization technique in which content is presented to the search engine spider that is different from that which is presented to the user's browser.
Cloaking is done by delivering content that is based on the IP addresses or the User-Agent HTTP header of the user that is requesting the page.
Cloaking is also a black hat SEO technique that should not be done and could get your website hit with a penalty or even deranked from Google.
In the context of Google Cloaking when you show different content to users than to the Googlebot "Google's Search Crawler" with the intent of manipulating search rankings and misleading both search engines and users is a serious policy violation of Google's policies.
Cloaking compromises search integrity.
And detecting of cloaking can lead to penalties like lower search engine rankings, removal from Google's search index or even being completely banned from Google's search results.